Transformation. Griffith differentiated SF (capsulated) & RF pneumonia. RFcaused disease in a mouse, by acquiring the capsule of the SF. Avery found that when Nucleic Acids were transferred from SF to RF, RF was able to form a capsule and cause disease.

Use both belowa. Sulfadrugs: Competitive inhibition for PABA (not completely success)b. Trimethropin: Works on Enzyme Bc. How do they work?

i. Enzyme A: PABA binds here = products

ii. Enzyme B: Products of A bind to B = Products2

iii. Products2 = Nucleic acid synthesis

What is the difference between antibiotic and antibacterial?

Similar, antibacterial is specific to bacteria.

What are the (4) ways that antibacterial resistance can occur? Give examples.

1. Alter enzyme. B. Lactamase.

2. Alteration of bacterial target site

3. Stop uptake of drug

4. MDR Pump in membrane: pumps drug out of itself

Describe what you can target as an anti-fungal?

Plasma Membrane

1. Eigosterols: Fungal cells vs. Cholesterol: Animal cells.

a. Drugs:

i. Amphoterism B (Ex. Tenactin)

ii. Miconazonle (Ex. monostat)

How can using differential media be useful?

You can use two different samples bacteria growing on the same media, the observations of the growth can differentiate the bacteria.

An example of ________ media is selenite broth, used for primary isolation of enteric bacteria. Other bacteria might usually dominate, but with selenite broth, this bacteria will flourish.

Enrichment media

MacConkey agar contains lactose as a substrate and neutral red as an indicator. Bacteria fermenting lactose produce acid and this will change the colour of the indicator and thus the colonies will turn red. The red lactose fermenting colonies can be differentiated from the pale non-lactose fermenting colonies. This is an example of _______ media.

Differential Media

_________ media will permit the growth of a particular pathogen and inhibit the other bacteria. In addition, it may be called _______ media when you can visually see the difference between the pathogen and the other bacteria that grow by the color and opacity of the colonies e.g. blood tellurite medium for C.diphtheriae.

Selective, Differential

What is CFU?

Colony forming units

How can you count bacteria indirectly?

By-products of metabolism (ATP, CO2)

Dry weight

or turbidity = mass spectrometry

What are the problems with counting bacteria via mass spectrometry?

Light scatter, other materials in the sample might change results.

What is the bacterial growth curve

The phases of growth

lag phase

log phase

stationary phase

death phase (log death)

E. Coli in stationary phase is placed in sterile broth. The bacteria increase in cell size, but do not divide until they reach the cell size of division during exponential growth. This phase is called ______ phase.

Lag

E. Coli concentration has increased so much, that the environment can no longer support exponential growth. Cell division rate now equals cell death rate. Or, number of viable cells = number of dying cells. This phase is called ______ phase.

Stationary

The cells in a culture are dividing back-to-back and total number of cells is increasing from 2 to 4 in the first 20 minutes, then 4 to 8 in the second 20 minutes. This phase is called ______ phase.

Log

How can you describe the symptoms of the host during each stage of microbial growth?

Lag phase: May not see symptoms

Log phase: Greatest signs/symptoms occur

Stationary: Symptoms slow/stop

In what phase are antibiotics most effective against bacteria and why?

Log phase. Antibiotics effect RNA/DNA transcription and translation, so it is most effective when most cell division is occurring.

Define gene. Genetic and molecular.

Genetic: Heredity

Molecular:

name given to some stretches of DNA and RNA that code for a polypeptide or for an RNA chain that has a function in the organism.

Phenotype

Expression of the genes possessed by the organism. May be dependent on environmental factors.

The genotype of an organism is the inherited instructions it carries within its genetic code.

- May not always result in the same look or behavior (environmental)

organisms that look alike necessarily have the same genotype.

Chromosome

Genetic information (DNA nucleotide chain) of an organism wound together w/proteins and stored.

Nucleotide

Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA.

Codon

A sequence of 3 nucleotides on the DNA strand that code for a specific amino acid as part of a poypeptide (protein/enzyme).

What is transfer RNA?

tRNA provides the anti-codon match to the codon from mRNA. Each tRNA is associated with an amino acid and is used in protein synthesis.

What are 3 types of gene expression?

1. Constitutive genes: Constantly on - Basic Function - Housekeeping

2. Induction: Genes that are turned on

3. Repression: Genes that are turned off

What is an operon's function?

Regulate a cluster of genes.

What are secondary messengers? Name them.

They are on/off switches for operons, CAPm cAMP.

3 prime ends with a? 5 prime ends with a?

3: Hydroxyl

5: Phosphate

Semiconservativism

Always use parent strand in DNA replication.

What is a transposon?

A plasmid that can "jump" genetic info into the host DNA. Carries R Gene. Must have a cell to reproduce, can't on it's own.

What is rRNA?

Ribosomal ribonucleic acid (rRNA) is the RNA component of the ribosome, the enzyme that is the site of protein synthesis in all living cells. Ribosomal RNA provides a mechanism for decoding mRNA into amino acids and interacts withtRNAs during translation by providing peptidyl transferase activity. The tRNAs bring the necessary amino acids corresponding to the appropriate mRNA codon.

What is DNA polymerase? RNA Polymerase?

Creates DNA chain, proofreads, Removing primer. DNA-DNA. DNA-RNA

What is a functional product?

Protein

what is DNA ligase?

Seals nucleotides in place/together.

Where does RNA come from?

DNA - Transcription

Describe the Kirby Bauer method.

An antibiotic disc diffusion test in which a you take one bacteria type and create a lawn of bacteria for comparison. Put a disk of absorbed antibiotic on the lawn in each quadrant (4 different antibiotics). After culturing, look for a zone of clearing or zone of inhibition around the discs.

Zone of inhibition

Zone of clearing around the disk means the organism is susceptible to the chemical. A larger zone means the organism is more susceptible to that chemical.

What is Ireimectin

Antiparasitic or helminth drug.

What are examples of where tape worms are found?

Raw beef, raw pork, raw fish.

Describe characteristics of viruses (8).

1. Small

2. Obligate parasite

3. No metabolism

4. No cellular structure

5. Host Cell specificity

6. Recognize specific host cell receptors

7. Capsid: Protein coat

8. Nucleic acid: DNA or RNA

Is a virus alive?

Many components of life are missing, but it can replicate. It has DNA/RNA.

A bacterium S. marcesens is found to be red and producing an antibiotic/toxin. Describe this environment and how it affects the genes.

At 37 C, S. marcesens produces a toxin/antibiotic by activating genes which produce an enzyme that creates the toxin. This genetic feature is important because it allows S. marcesens to kill off and out-compete other organisms for resources. At 25 C it does not produce this toxin, stays white, and instead functions more optimally, focusing on metabolism and growth.

You need to determine if an organism is micrococcacae or streptococcaceae. Or you need to identify mycobacterium. What test will you use? What results do you expect to see.

Catalase test. Micrococcaceae will bubble when hydrogen peroxide is added. Streptococcaceae will not. This may be performed on a slide or slant. E. Coli will not contain catalase. S. Aureus has catalase.

You need to determine if an organism can break down gelatin. What test do you perform and what do you expect to see?

Why do organisms secret lipase? How does this affect results using spirit blue agar?

Organisms must break down the tributyrin triglyceride in spirit blue agar before it can be absorbed and metabolized. This process causes clearing or halos surrounding the growth (ex. P. Mirabilis and S. aureus, not E. coli).

What tests might you perform to determine if something is sanitary or if it contains coliform bacteria?

Red or pink color is positive for indole. This means that the enzyme for break down of tryptophan is present.

Which tube represents a positive result for methyl red? What does a positive result mean?

The tube on the right, a red test tube is a positive result. This means the bacteria is doing a mixed acid fermentation (overcomes phosphate buffer and reduces pH).

Which one is positive for VP.

Red or dark layer of reddening is positive. No color change is negative. Indicates the presence of acetonin (MR indicates presence of acid as comparison)

Which is positive for the citrate utilization test?

Blue.

Explain the effect of UV radiation on microbial growth.

UV radiation causes Thymine dymers which causes death and will sterilize an object if applied for an adequate amount of time. At 90 and 120 seconds very little evidence of bacterial survival was seen for E. coli and B. Cereus when exposed to UV radiation.

Why might you observe small plaques in a lawn of bacteria?

The bacteria have been infected by a bacteriophage. As a host cell lysis occurs and phage infects others, a clearing of cells or a plaque (3-7mm) forms. Additionally a turbid halo may be observed around the plaque.

Yellow w/ bubbles= Fermentation w/ acid and gas end productYellow with no bubbles= Fermentation with acid end product and no gas productionOrange/red w/ no bubbles= no fermentationPink/ no bubbles= degradation of peptone; alkaline end products

Which tests utilize

Methyle Red

MR-VP(Acid from glucose-Acetoin)

Reagent for VP test

Hydroxide & (looking for acetoin)

How do you test for PFUs?

And what does acronym stand for?

Plaque Assay test: determines viral particles in a sample.

Plaque Forming Unit

"plaques" are lysis clearings on agar plate

What two steps are involved with preparing the Plaque Assay test?

Add microbes at different dilutions to nutrient broths and allow 15 minute preabsorption period (phages need time to attach to bact cells)

Next pour into agar plates and incubate.

View for plaques

What enzyme can be used to raise the pH of the body/an organism?

Decarboxylase

What enzyme could be used to break down a blood clot?

hemolysin

Acetoin is detected by what two reagents in the VP test?

potassium hydroxide

a-napthol are added on the second day

Explain why there are three different types of medium used for decarboxylase tests.

Each decarboxylase enzyme produced by an organism is specific to the amino acid on which it acts.

(Lysine decarb.

Arginine decarb.

Orthnithine decarb)

What are the three amino acids we commonly test for their ability to be decarboxylated ?

arginine, lysine, and ornithine.

Results for Mannitol Salt Aagar plate

G + cocci

Yellow growth= prduces acid from Mannitol fermentation

Red growth= No Mannitol Fermentation

Poor/no growth= Organism is inhibited by salt

Phenol red- pH indicator

What enzyme could you use to metabolize triglycerides (for glycolysis)?

Lipase

MacConkey Agar

Selective/differetial media

Contains: Lactose, bile salts, neutrsl red dye, and crystal violet

Ble salts and crystal violet inhibit gram + growth

Neutral red dye is the pH indicator

LACTOSE FERMETSTION

Results for MacConkey Agar Plate

G - rod eterics

Green or red growth= produces acid from lactose fermentation

Colorless growth-Does NOT ferment lactose

Poor/no growth=inhibited by crystal violet and/or bile salt

how indol is detected

?

results

Tryptophanis btoken down into Indol and pyruvic acid using Kovac's Reagent

Hydrolysis of tryptophan in SIMS can be detected by adding Kovac's reagent. Indol reacts with Kovac's reagent

Results

+ Red in alcohollayer of Kovac= Tryptophan broken down indol and pyruvic acid

- Reagent No color change= Tryp not broken down

How Sulfide is detected

and Results

H2S is detected by their action with ferous ammonium sulfate in the medium

Results

+ Black in medium=Sulfer reduction (H2 prodution)

- no black in medium= Sulfer no reduced

Mixed acid fermentation

MR test

Overcomes the phospate buffer in the medium and lowers the pH (acidic)

restriction enzyme prevents replication of the phage DNA by cutting it into many pieces. Restriction enzymes were named for their ability to restrict, or limit, the number of strains of bacteriophage that can infect bacteria.

LysogenyVirus becomes one with host cell genome replicating the virus each time the bacteria replicates

In Biosynthesis A, Transcription and translational machinery are turned ON.In Biosynthesis B, T & T are turned OFF because virus takes over cell.

Lysogentic Phase

Attachment and penetration same as Lytic. BioA- virus becomes one with host cell now called, Integration and Prophage.BioB- Induction- once induces then it leavesAssembly/maturation same as lytic phase

2 Types of TransductionOnly for Lysogenic

1. Specialized- virus is transfered specific gene from 1 cell to another

2. Generalized- any gene can be tranfered from one bacterial cell to another via bacteriaphage.

Biosynthesis 3bLysogenic phase

Transcriptional and translational properties are not turned off and the virus is still replicating by the host cell. Can stay in host cell genome forever but not going to.

Induction - Lysogenic phase

Signal virus responds to to releaseInduces itself to release

Latent Virus

Smae as Lysogenic virus but in Animal/plant cells

How Animal/plant viruses attach to the cell

animal viruses have to recognize the specific host cell and attach by the Spikes

Bind up free floating ironReason binding our body is trying to keep the iron away from the bacteria cells. Bacteria cells need the iron to grow because it uses the iron as a co-factor. our bodies sre going to takw it and bind it up.

what does phagocytosis mean ?

cell eating

Phagocytes

Leukocytes that perform PhagocytosisAll Phagocytes are leukocytes but not all leukocytes are Phagocytes

When virus makes the capsid it is formed into one long strand. What cuts the capsid up into individual pieces?

Protease

Protease Inhibitor drugsStopping drugs from replicating using assembly and maturation

The complex is placed on the cell poking holes in the cell and making it explodeWorks better in G - cells because G+ cells have a thicker peptoglycan layer than G -. If one from C5b-C9 is missing it wont work

Interferon- antiviral

Chemical messanger Sent from Host cell A to Host cellB telling B what antiviral to synthesizeDoes not go into the cell.

Allergies are partly due to the synthesis of IgE. Due to this antibody, the allergy produces an exaggerated host immune response in the host. So scientist are attempting to use an allergic response to cure certain types of diseases. Which of the following is being mixed to produce an allergic response to cure kidney disease. Parasitic cells? Human Kidney cells? Bacterial cells? A and B? B and C?

A and B. Mix parasitic cells with with IgE to make sure the IgE produced will work with the patient's cell. We want the IgE to bind to his kidney cells.

major histocompatibility complex(MHC) molecules (the other one being MHC class II) and are found on every nucleated cell of the body

Define neutrophil

Neutrophil granulocytes are the most abundant type of white blood cells, the innate immune system. Called: neutrophils or polymorphonuclear neutrophils (or PMNs), Neutrophils are normally found in the blood stream. During the beginning (acute) phase of inflammation, particularly as a result of bacterial infection.

Bacterial DNA (instead of viral) is packaged into the viral capsid by mistake. Bacterial DNA is transferred to a new bacterium via bacteriophage virus. Conjugation may occur where new DNA is inserted into the bacterium's DNA. Also called recombination.

Describe specialized transduction.

Error - some bacterial DNA packaged with bacterial DNA.

Describe prophage

Viral Nuc. Acids integrated into bacterial DNA chromosome. In Lysogenic cycle; it is integrated into the host chromosome or exists as an extrachromosomal plasmid. Called prophage only while the viral DNA remains incorporated in the host DNA. This is a latent form of a bacteriophage

Give examples of lysogenic viruses

- Epstein Barr

- Herpes Zoster

- Herpes Simplex I, II

- Hepatitis

- HIV

What type of cancer does Epstein Barr (Mono) cause?

B and T cell cancer

What type of cancer is HIV associated with?

Kaposis sarcoma (connective tissue)

What factors affect virus expression?

Stress

How do viruses stimulate cancer? What percentage of cancers are linked to a virus?